Impact of probe compound in MRP2 vesicular transport assays

Eur J Pharm Sci. 2012 May 12;46(1-2):100-5. doi: 10.1016/j.ejps.2012.02.016. Epub 2012 Mar 3.


MRP2 is an efflux transporter that is expressed mainly in the canalicular membrane of hepatocytes, where it expels polar and ionic compounds into the bile. MRP2 is also present in the apical membrane of enterocytes and epithelial cells of proximal tubules of the kidney. Inhibition of MRP2 transport can lead to the accumulation of metabolites and other MRP2 substrates up to toxic levels in these cells. The transport properties of MRP2 are frequently studied with the vesicular transport assay. The assay identifies compounds that interact with MRP2 by measuring the effect of a compound on the transport of a radioactively labeled or fluorescent probe. We have compared the effect of eight selected test compounds (quercetin, disopyramide, paracetamol, indomethacin, diclofenac, estrone-3-sulfate, budesonide, and thioridazine) on the MRP2-mediated transport of three commonly used probes: 5(6)-carboxy-2,7-dichlorofluorescein, leukotriene C4 and estradiol-17-β-d-glucuronide (E217βG). Five of the test compounds had different probe-dependent effects on the MRP2-mediated transport, suggesting differences in the transport mechanism of the probes. Our results underline the complexity of substrate recognition by these efflux transporters and the difficulties in directly comparing results obtained with different assays, especially when different probes are used.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / pharmacology
  • Animals
  • Baculoviridae
  • Biological Assay
  • Biological Transport
  • Budesonide / pharmacology
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Diclofenac / pharmacology
  • Disopyramide / pharmacology
  • Estradiol / analogs & derivatives*
  • Estradiol / pharmacokinetics
  • Estrone / analogs & derivatives
  • Estrone / pharmacology
  • Fluoresceins / pharmacokinetics*
  • Genetic Vectors
  • Humans
  • Indomethacin / pharmacology
  • Inhibitory Concentration 50
  • Leukotriene C4 / pharmacokinetics*
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins / agonists
  • Multidrug Resistance-Associated Proteins / antagonists & inhibitors
  • Multidrug Resistance-Associated Proteins / metabolism*
  • Quercetin / pharmacology
  • Recombinant Proteins / metabolism
  • Spodoptera
  • Statistics as Topic
  • Thioridazine / pharmacology
  • Transfection


  • ABCC2 protein, human
  • Fluoresceins
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins
  • Recombinant Proteins
  • 5(6)-carboxy-2',7'-dichlorofluorescein
  • Diclofenac
  • estradiol-17 beta-glucuronide
  • Leukotriene C4
  • Estrone
  • Acetaminophen
  • Estradiol
  • Budesonide
  • Quercetin
  • Disopyramide
  • Thioridazine
  • estrone sulfate
  • Indomethacin